LEXUS GS400 2000 Service Repair Manual

I04046
Wire Harness Side BE±58
± BODY ELECTRICALTURN SIGNAL AND HAZARD WARNING SYSTEM
2359 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. INSPECT TURN SIGNAL FLASHER CIRCUIT
Disconnect the connector from the combination switch and in-
spect the connector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantContinuity
3 ± GroundConstantContinuity
5 ± GroundTurn signal switch RIGHT or OFFNo continuity
5 ± GroundTurn signal switch LEFTContinuity
6 ± GroundTurn signal switch LEFT or OFFNo continuity
6 ± GroundTurn signal switch RIGHTContinuity
7 ± GroundConstantContinuity
8 ± GroundHazard warning switch OFFNo continuity
8 ± GroundHazard warning switch ONContinuity
1 ± GroundIgnition switch LOCK or ACCNo voltage
1 ± GroundIgnition switch ONBattery positive voltage
4 ± GroundConstantBattery positive voltage
If circuit is as specified, replace the relay.
If circuit is not as specified, inspect the circuits connected to oth-
er parts.

BE0GY±05
I01354
Front Personal Light
Rear Personal Light
Door Courtesy Light
Licence Plate Light Luggage Compartment Light
Door Courtesy Lights
Luggage Compartment
Courtesy Switch
Door Courtesy Light
Vanity Light
Vanity Light
Rheostat Light Control
Glove Compartment
Door Courtesy Light
Glove Compartment
Door Courtesy Switch
Passenger Side Junction Block

DOME Fuse

Body ECU No.1
Driver Side Junction Block

Body ECU No.2
Luggage
Compartment
Key Lock and
Unlock Switch
Rear Personal Light Rear Personal Light
± BODY ELECTRICALINTERIOR LIGHT SYSTEM
BE±59
2360 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INTERIOR LIGHT SYSTEM
LOCATION

I04047
DOOR OFF ON
DOOR OFF ON w/ Sliding Roof w/o Sliding Roof
BE0GZ±03
I04048
Wire Harness Side BE±60
± BODY ELECTRICALINTERIOR LIGHT SYSTEM
2361 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT FRONT PERSONAL LIGHT SWITCH CONTI-
NUITY
Switch positionTester connectionSpecified condition
Interior light switch
OFF (Lever switch)±No continuity
Interior light switch
DOOR (Lever switch)1 ± 3Continuity
Interior light switch
ON (Lever switch)1 ± 2Continuity
*Personal light OFF
(Push switch)±No continuity
*Personal light ON
(Push switch)1 ± 2Continuity
*: Set the interior light switch to OFF or DOOR.
If continuity is not as specified, replace the light assembly or
bulb.
2. INSPECT FRONT PERSONAL LIGHT SWITCH CIR-
CUIT
(See page DI±843)
Disconnect the connector from the switch and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantContinuity
1 ± GroundConstantBattery positive voltage
If circuit is not as specified, inspect power source or wire har-
ness.

I04049
I04048
Wire Harness Side
I04050
21
OFFON
± BODY ELECTRICALINTERIOR LIGHT SYSTEM
BE±61
2362 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT REAR PERSONAL LIGHT SWITCH CONTI-
NUITY
Switch positionTester connectionSpecified condition
Room light switch
OFF and door closed±No continuity
Room light switch
ON and door closed1 ± 2Continuity
Room light switch OFF or
ON and door opened1 ± 3Continuity
If continuity is not as specified, replace the light assembly or
bulb.
4. INSPECT REAR PERSONAL LIGHT SWITCH CIRCUIT
Disconnect the connector from the switch and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantContinuity
1 ± GroundConstantBattery positive voltage
If circuit is not as specified, inspect power source or wire har-
ness.
5. INSPECT VANITY LIGHT CONTINUITY
Switch positionTester connectionSpecified condition
OFF (closed)±No continuity
ON (opened)1 ± 2Continuity
If continuity is not as specified, replace the vanity light assembly
or bulb.

I04051
Wire Harness Side
I04061
Open Close
1 2
BE±62
± BODY ELECTRICALINTERIOR LIGHT SYSTEM
2363 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. INSPECT VANITY LIGHT CIRCUIT
Disconnect the connector from the light and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantContinuity
1 ± GroundConstantBattery positive voltage
If circuit is not as specified, inspect power source or wire har-
ness.
7. Front door:
INSPECT DOOR COURTESY SWITCH CONTINUITY
(a) Connect the connector to the front door ECU.
(b) Check that continuity exists between terminals 1 and 2
when door is opened.
(c) Check that no continuity exists between terminals 1 and
2 when door is closed.
If continuity is not as specified, replace the switch.
8. Front door:
INSPECT DOOR COURTESY SWITCH CIRCUIT
Driver side: (See page DI±868)
Passenger side: (See page DI±900)

I04066
Open Close
1 2
I04052e±2±2±J
21
I04053
Wire Harness Side
I04054
1 2
± BODY ELECTRICALINTERIOR LIGHT SYSTEM
BE±63
2364 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
9. Rear door:
INSPECT DOOR COURTESY SWITCH CONTINUITY
(a) Connect the connector to the rear door ECU.
(b) Check that continuity exists between terminals 1 and 2
when door is opened.
(c) Check that no continuity exists between terminals 1 and
2 when door is closed.
If continuity is not as specified, replace the switch.
10. Rear door:
INSPECT DOOR COURTESY SWITCH CIRCUIT
Rear LH side: (See page DI±930)
Rear RH side: (See page DI±947)
11. INSPECT DOOR COURTESY LIGHT CONTINUITY
Using an ohmmeter, check that continuity exists between termi-
nals.
If continuity is not as specified, replace the light assembly or
bulb.
12. INSPECT DOOR COURTESY LIGHT CIRCUIT
Driver side: (See page DI±874)
Passenger side: (See page DI±906)
Rear LH side: (See page DI±934)
Rear RH side: (See page DI±951)
13. INSPECT LUGGAGE COMPARTMENT DOOR COUR-
TESY SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
OFF (closed)±No continuity
ON (opened)2 ± Switch bodyContinuity
If continuity is not as specified, replace the switch.

I04185
Wire Harness Side
I04056e±2±2±J
I04053
Wire Harness Side BE±64
± BODY ELECTRICALINTERIOR LIGHT SYSTEM
2365 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
14. INSPECT LUGGAGE COMPARTMENT DOOR COUR-
TESY SWITCH CIRCUIT
(See page DI±792)
Disconnect the connector from the switch and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± Body groundLuggage compartment door courtesy switch ON
(door opened)Continuity
If circuit is not as specified, inspect power source or wire har-
ness.
15. INSPECT LUGGAGE COMPARTMENT LIGHT CONTI-
NUITY
Using an ohmmeter, check that continuity exists between termi-
nals.
If continuity is not as specified, replace the light assembly or
bulb.
16. INSPECT LUGGAGE COMPARTMENT LIGHT CIR-
CUIT
Disconnect the connector from the light and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
1 ± Body groundConstantContinuity
If circuit is not as specified, inspect power source or wire har-
ness.

I04057
ONOFF
1 2
I04058
Wire Harness Side
12
I04059e±2±2±J
1 2
± BODY ELECTRICALINTERIOR LIGHT SYSTEM
BE±65
2366 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
17. INSPECT GLOVE COMPARTMENT DOOR COURTE-
SY SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
OFF (closed)±No continuity
ON (opened)1 ± 2Continuity
If continuity is not as specified, replace the switch.
18. INSPECT GLOVE COMPARTMENT DOOR COURTE-
SY SWITCH CIRCUIT
Disconnect the connector from the switch and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantContinuity
1 ± GroundLight control switch OFFNo voltage
1 ± GroundLight control switch TAIL or HEADBattery positive voltage
If circuit is not as specified, inspect power source or wire har-
ness.
19. INSPECT GLOVE COMPARTMENT LIGHT CONTINU-
ITY
Using an ohmmeter, check that continuity exists between termi-
nals.
If continuity is not as specified, replace the light assembly or
bulb.

I04053
Wire Harness Side
I04060e±2±2±J
I04053
Wire Harness Side BE±66
± BODY ELECTRICALINTERIOR LIGHT SYSTEM
2367 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
20. INSPECT GLOVE COMPARTMENT LIGHT CIRCUIT
Disconnect the connector from the light and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundGlove compartment door courtesy switch ONContinuity
1 ± GroundLIght control switch in TAIL or HEADBattery positive voltage
If circuit is not as specified, inspect power source or wire har-
ness.
21. INSPECT LICENCE PLATE LIGHT CONTINUITY
Using an ohmmeter, check that continuity exists between termi-
nals.
If continuity is not as specified, replace the light assembly or
bulb.
22. INSPECT LICENCE PLATE LIGHT CIRCUIT
Disconnect the connector from the light and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
1 ± GroundConstantContinuity
2 ± GroundLight control switch TAIL or HEADBattery positive voltage
If circuit is not as specified, inspect power source or wire har-
ness.

BE0GW±08
I01355
Ignition Switch
Driver Side Junction Block

GAUGE Fuse
Back±up Lights
Park/Neutral Position Switch
± BODY ELECTRICALBACK±UP LIGHT SYSTEM
BE±67
2368 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
BACK±UP LIGHT SYSTEM
LOCATION